Q&A: Dark Matter

Description:
Questions and answers about this "term used to describe the mass in galaxies and clusters whose existence we infer from rotation curves and other techniques, but which has not been confirmed by observations on any electromagnetic wavelength." Topics include black holes, parallel universes, gravity, and more. Includes the related essay, "Dark Matter Mystery." From the Chandra X-Ray Observatory, operated for NASA by the Smithsonian Astrophysical Observatory.